Gear-cutting machine.



W. F.'FOLMER.

GEAR CUTTING MACHINE. I APPLICATION man 050.12. 1914.

Patented Apr. 3, 1917.

4 SHEETS-SHEET I.

anvanto'v W. F. FOLMER.

GEAR CUTTING MACHINE.

APPLICATION FH .ED DEC. 12. 19 .4.

Iibed Apr. 3, 1917 I Pate LQQL3U3.

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w. F. FOLMQERL GEAR CUTTING MACHINE.

APPLICATION FILED DEC. 12, 19M.

Patented Apr. 3, 1917.

4 SHEETS-SHEET 3.

'WVF. FOLMER.

GEAR CUTTING MACHINE. APPLICATION FILED 0Ec.12. 19-14.

Patented Apr. 3,1917.

4 SHEETS-SHEET 4.

men .a i i cans are PTEZWT onshore...

"WILLIAM F. FOLMER, fill BOGHESTER, NEW YQRK, AESSIGNOR T EASTMAN KODAK 00., 013 ROCHESTER, NEW YGBK, A CORPORATION OF NEW YORK.

onaitcormine MACHINE.

Specification of Letters Patent.

Patented Apr. 3, i ilt.

Application filed December 12, 1914. Serial No. 376,965.

To all whom it may concern."

Be it known that 1, WILLIAM F. FOLMER, of Rochester, in the county of Monroe and State of New York, have invented certain new and useful Improvements in Gearilutting; llzlachines; and I do hereby declare the following to be a full, clear, and exact description of the same, reference being had to the accompanying drawings, forn'iing a part of this specification, and to the reference numerals marked thereon.

My present invention relatcs'to gear cutting mecl'ianism and it has "for its special object to provide a simple and durable ma chine which is capable of cutting gear teeth with extreme accuracy and speed. A further object is to provide a cutter member for gradually increasing the depth oi cut in the work piece by a continuous progressive action and, working in conjunction with said cutter, a work advancing member coiipating with the teeth as they are completed by the cutter. 'l he invention also includes a work guide having certain adjustable 'l ea tures whereby a proper conjoint action between the cutter and workpiece may be effooted. To these and other ends the invention consists in certain. improvements and combinations of parts, all. as will be herein after more fully described, the novel teatures being pointed out in the claims at the end of the specification.

in the drawings:

Figure 1 is a side elevation of a gear cutting machine constructed in accordancewith and illustrating one embodiment of my invention, the machine being; adapted for cutting rack bars;

Fig. 2 is a "front view thereof;

Fig. 3 is a sectional plan view on the line 3---3 of Fig. 1;

Fig. 4t is an enlarged sectional view on the line ll of Fig. 3;

Fig. 5 is a similar View on the line 5-5 of Fig. 3;

Fig. 6 is a plan View of a modified structure;

Fig. Z is a -front view thereof;

Fig. 8 is a vertical sectional View on the line 8-8 of Fig. 6;

Fin. 9 is a plan view showing the feed rollers and their driving mechanism in detail, and

Fig. 10 is an enlarged face view of the cutter.

Similar reference numerals throughout the several figures indicate the same parts.

In illustrating my present invention, I have shown a machine especially adapted for the formation of rack bars and which was designed for cutting racks for the focus ing mechanism of camera beds. in. carrying out the invention, as illustrated in the present embodiment, I employ a rotary cutting member or hob provided with helically arranged cutting teeth coiipcrating with a work strip fed to the cutter in. a direction substantially parallel to the unis thereof. A work advancing screw arranged adjacent the cutting member and. revolving therewith, engages the completed teeth on the work stri J as it passes said cutting member and fee s the strip at a uniform speed. The work guide and cutter are adjustable relatively toward and from each other to pen mit the use of stock of differing thicknesses and angularly adjustable about the point at which the work piece crosses the periphery of the cutter to enable the work/snap to be disposed at right angles with the direction of motion of the cutting teeth, said angular adjustment being more or less pronounced according to the pitch angle of the work advancing thread.

In the drawings, a table 1 is provided with a support 2 on which is mounted in bear-- ings 3 a rotating shaft 4: cariyingthe cut ting hob 5 at its outer end and driven by a pulley 6. The support 2 has a dependi" portion 7 on which a bracket or shell is vci tically movable'on a guide 8 by adjustment of the micrometer screw 9, and is firmly secured in its adjusted position by clamping bolts 10. The work guide A is carried by a member 11 resting on the top of the bracket and pivoted on a boss 12 on the bracket located at a point substantially opposite the center of the hob 5, the guide .th being thus angularly adjustable with relation to the hob about an axis extending radially through the periphery of the hob. The guide A in the present instance is made oi" hardened material that will resist wear and is readily removable from the ways 12, and embodies lateral walls 14 and a thrust wall 15. A work piece held between the lateral walls 14 becomes adjustable at an angle to .the hob by swinging the member 11 about its pivot, the angle being indicated by the graduations 16 on the edge of the bracket 8, and the member 11 is secured after adjustment by the bolts 17. The thrust wall 15 is adjustable toward the axis of the shaft 4 by vertical movement of the bracket 18, the amount of movement being indicated by the graduations 19 on the depending porthe diameter at the root of the threads as shown in Fig. 5. From this figure, it will be seen that if the stock operated upon runs a small amount over size, the conical teeth will take oif just enough to make all the teeth the proper length. The teeth on the hob being of gradually increasing length, increase the depth of the cuts in the work until by the time the latter has-reached the inner end of the hob, the teeth thereon are fully formed, 1

The work advancing screw 25 is secured immediately adjacent the hob, to which it is secured by a dowel pin 26 and screws 27. The threads 26' on the screw 25 engage the work just after the teeth thereon are completed by the hob and advance it at a uniform rate. On account of the power required to feed the work being distributed to several teeth,- there is no undue strain brought upon any one tooth, the smooth surfaces of the threads 26 burnish the teeth .on the rack and remove any imperfections in size or shape, which may have been caused by the cutting teeth.

The hob is made of larger diameter than the driving pulley 6 and the-support 2-is recessed at O beneath the bearings 3 to permit free passage of the work piece as it is fed through the machine.

On account of the large size of the hob compared to the width of the rack tooth, the curve in the direction of length of the teeth approximates very nearly a straight line thereby reducing the theoretical error to a negligible quantity and producing a rack bar of high efficiency in operation. In case it is desired to cut racks with different sized teeth, a suitable hob is provided for each size. The pitch angle of the teeth will be different for each size, and in changing from one size hob to another it will be spondingly to dispose the direction of the in which the cutting teeth move. In some cases it may be desired to cut the teeth in the work piece at other than a right angle to its length.

In Figs. (3 to 9 I have shown a modified structure in which the work is fed positively during its insertion into the machine. In these figures, the hob shaft 4: is arranged at a right angle to the shaft at carrying the driving pulleys 6, and is driven by means of the miter gears 30. The standard 1 has rigidly secured thereto a table 31 carrying brackets 32 on which are vertically adjustable brackets carrying the slielves 34. An angularly adjustable member 35 is pivoted at 37 to the table 31 on the support at a point opposite the .hob to swing about an axis extending radially through the periphcry of the hob, and a bracket 35 carrying the work guide 36 is adjustable on said member toward the axis of the hob. The guide may be adjusted at an angle to the .hob by shifting the member 35 about its axis 37 and securing it by means of the bolts as. upper side with a guide way in which two slides 39 are adjustable by means of set screws 40. Vertical shafts 4L1, journaled in said slides, carry at their upper ends driving rolls 42 hearing on opposite sides of the work piece and at their lower ends worm wheels 43 engaging worms 44 on a shaft 45 journaled in the member 35. The shaft 45 is provided at its outer end with a gear 46 meshing with a gear 47 carried on a lever arm movable about the shaft 45 as a center, said gear 47 being connected to a sprocket wl'toel 48 driven from. a sprocket wheel 4-!) on the shaft lby means of a chain 50.

The peripheral speed of the rollers is timed to be exactly the same as that at which the screw 25 advances the work, consequently the work is fed at the proper speed when the hob begins to act upon it and the teeth are properly formed. Inlong strips, the work pieces are quite'flexible, and it is desirable that they be guided straight for quite a distance to each side of the cutting point so as to avoid causing any stresses in the material during the cutting operation.

To this end, adjustable guides 51 are provided on both of the shelves 34 in addition to the guide 36 and springs 52 holdthe work in frictional engagement with them and exert a dragging effect on the work that tends to diminish vibration.

I claim as my invention:

" work piece at a right angle to the direction This member 35 is provided on its 1. In a machine for cutting gear teeth,

menace r otatably mounted on the support, and a Work guide angularly adjustable with relation to the hob about an axis extending substantially radially through the periphcry of the hob, one of said parts being mov able about said axis as a center While the other remains fixed.

2. In a. machine for .cutting gear teeth, the combination With a support, of a rotatable cutter carried by the support, having cutting teeth on its periphery, a Work guide for guiding a Work piece across the periphery of the cutter, the Work guide and cutter being relatively adjustable angularly about an axis extending substantially radially through the periphery of the cutter, and means for feeding the work piece.

3. In a machine for cutting gear, teeth, the combination with a support, ot a rotatable cutter carriedby the su 'iport having cutting teeth on its periphery, a work guide for guiding a Work piece across the periphery of the cutter, the cutter and Work guide being relatively adjustable angular-1y about an axis substantially perpendicular to the periphery of the cutter, and means for feeding the work piece.

4. In a. machine for cutting gear teeth, the combination with a support, of a rotatable cutter carried by the support having cutting teeth on its periphery, a, Work guide for guiding a Work piece across the periphcry of the cutter, adjustable with. relation to the cutter about an axis extending substantially radially through the periphery thereof, and means for feeding the Work piece. 1

5. Ina machine for cutting gear teeth, the combination with a support, of a rota table cuttercarried by the support and having cutting teeth on its periphery, a bracket carried by the support and movable to Ward the cutter and. a-u'ork guide for guiding a work piece across the periphery oi": the

cutter. said guide being angularly ad ustable 1 upon the bracket with relation to the cutter about'an axis extending substantially radially through the periphery oi. the cutter, and securing means for holding the Work guide in adjusted relation on the bracket.

WILTJA M F. FOLMER. \i'itnesses RUSSELL l3. (hurrrrli, Li. l9. S'roix'nnaAin-rn. 

